Supplementation with complex milk lipids during brain development promotes neuroplasticity without altering myelination or vascular density

BACKGROUND: Supplementation with complex milk lipids (CML) during postnatal brain development has been shown to improve spatial reference learning in rats. OBJECTIVE: The current study examined histo-biological changes in the brain following CML supplementation and their relationship to the observed improvements in memory. DESIGN: The study used the brain tissues from the rats (male Wistar, 80 days of age) after supplementing with either CML or vehicle during postnatal day 10–80. Immunohistochemical staining of synaptophysin, glutamate receptor-1, myelin basic protein, isolectin B-4, and glial fibrillary acidic protein was performed. The average area and the density of the staining and the numbers of astrocytes and capillaries were assessed and analysed. RESULTS: Compared with control rats, CML supplementation increased the average area of synaptophysin staining and the number of GFAP astrocytes in the CA3 sub-region of the hippocampus (p<0.01), but not in the CA4 sub-region. The supplementation also led to an increase in dopamine output in the striatum that was related to nigral dopamine expression (p<0.05), but did not alter glutamate receptors, myelination or vascular density. CONCLUSION: CML supplementation may enhance neuroplasticity in the CA3 sub-regions of the hippocampus. The brain regions-specific increase of astrocyte may indicate a supporting role for GFAP in synaptic plasticity. CML supplementation did not associate with postnatal white matter development or vascular remodelling.